Aromatization reactors with hydrogen removal and related reactor systems

Abstract

The present invention discloses aromatization reactor vessels with hydrogen membrane tubes, and associated aromatization reactor vessel systems. Also disclosed are processes for conducting aromatization reactions utilizing these reactor vessels and systems.

We claim: 
     
       1. An aromatization reactor vessel comprising:
 (a) a reactor wall; 
 (b) a catalyst bed positioned within the reactor vessel; 
 (c) an outer annulus positioned between the reactor wall and an outer particle barrier, the outer particle barrier and the outer annulus surrounding the catalyst bed; 
 (d) a reactor inlet for a feed stream; 
 (e) a reactor outlet connected to a center pipe, the center pipe positioned in the reactor vessel and surrounded by the catalyst bed;
 wherein a flow path for the feed stream begins at the reactor inlet, continues to the outer annulus, through the outer particle barrier and the catalyst bed, into the center pipe, and to the reactor outlet; and 
 
 (f) a membrane tube configured to remove H 2 , the membrane tube positioned in the center pipe or the outer annulus, the membrane tube having an inner permeate side and an outer process side. 
 
     
     
       2. The vessel of  claim 1 , wherein the membrane tube is positioned in the center pipe, and wherein the outer process side faces the center pipe. 
     
     
       3. The vessel of  claim 1 , wherein the membrane tube is positioned in the outer annulus, and wherein the outer process side faces the outer annulus. 
     
     
       4. The vessel of  claim 1 , wherein the membrane tube is configured for an operating temperature in a range from about 260° C. to about 600° C. 
     
     
       5. The vessel of  claim 1 , wherein the membrane tube comprises palladium. 
     
     
       6. The vessel of  claim 1 , wherein the center pipe and the catalyst bed are positioned concentrically. 
     
     
       7. The vessel of  claim 1 , wherein the aromatization reactor vessel is configured for a catalytic conversion of a non-aromatic hydrocarbon to an aromatic hydrocarbon comprising benzene, toluene, xylene, or combinations thereof. 
     
     
       8. An aromatization reactor vessel system comprising from two to eight aromatization reactor vessels in series, wherein at least one is the aromatization reactor vessel of  claim 1 . 
     
     
       9. The system of  claim 8 , wherein the aromatization reactor vessel system is configured to increase selectivity and to increase catalyst lifetime, as compared to an equivalent aromatization reactor vessel system without the membrane tube, under the same reaction conditions. 
     
     
       10. The vessel of  claim 1 , wherein the vessel further comprises an electrical system for inducing an electrical bias across the membrane tube to control a H 2  removal rate. 
     
     
       11. An aromatization reactor vessel system comprising from 2 to 8 aromatization reactor vessels in series, wherein at least one is an aromatization reactor vessel comprising:
 (a) a reactor wall; 
 (b) a catalyst bed positioned within the reactor vessel; 
 (c) an outer annulus positioned between the reactor wall and an outer particle barrier, the outer particle barrier and the outer annulus surrounding the catalyst bed; 
 (d) a reactor inlet for a feed stream; 
 (e) a reactor outlet connected to a center pipe, the center pipe positioned in the reactor vessel and surrounded by the catalyst bed;
 wherein a flow path for the feed stream begins at the reactor inlet, continues to the outer annulus, through the outer particle barrier and the catalyst bed, into the center pipe, and to the reactor outlet; and 
 
 (f) a membrane tube configured to remove H 2 , the membrane tube positioned in the reactor outlet, wherein the membrane tube has an inner permeate side and an outer process side, the outer process side facing the reactor outlet; 
 wherein a total amount of the catalyst in the aromatization reactor vessel containing the membrane tube and each preceding reactor vessel in the series is in a range from about 15 to about 50 wt. %, based on the sum of the catalyst contained in all of the reactor vessels in the system. 
 
     
     
       12. The system of  claim 11 , wherein the aromatization reactor vessel system is configured to increase selectivity, as compared to an equivalent aromatization reactor vessel system without the membrane tube, under the same reaction conditions. 
     
     
       13. The system of  claim 11 , wherein the aromatization reactor vessel system is configured to increase catalyst lifetime, as compared to an equivalent aromatization reactor vessel system without the membrane tube, under the same reaction conditions. 
     
     
       14. The system of  claim 11 , wherein:
 the system comprises from 4 to 7 aromatization reactor vessels in series; and 
 the total amount of the catalyst in the aromatization reactor vessel containing the membrane tube and each preceding reactor vessel in the series is in a range from about 20 to about 45 wt. %, based on the sum of the catalyst contained in all of the reactor vessels in the system. 
 
     
     
       15. An aromatization reactor vessel system comprising:
 (I) an aromatization reactor vessel comprising:
 (a) a reactor wall; 
 (b) a catalyst bed positioned within the reactor vessel; 
 (c) an outer annulus positioned between the reactor wall and an outer particle barrier, the outer particle barrier and outer annulus surrounding the catalyst bed; 
 (d) a reactor inlet for a feed stream; and 
 (e) a reactor outlet connected to a center pipe, the center pipe positioned in the reactor vessel and surrounded by the catalyst bed;
 wherein a flow path for the feed stream begins at the reactor inlet, continues to the outer annulus, through the outer particle barrier and the catalyst bed, into the center pipe, and to the reactor outlet; and 
 
 
 (II) a H 2  removal system configured to remove H 2  from a reactor effluent, wherein a H 2 :hydrocarbon molar ratio in the reactor effluent is reduced from within a range of about 4:1 to about 5:1 to within a range from about 1.5:1 to about 2:1, the H 2  removal system positioned downstream of the reactor outlet, wherein: 
 the H 2  removal system comprises a shell containing a membrane tube, 
 the reactor effluent passes through the shell, and 
 the membrane tube has an inner permeate side and an outer process side, the outer process side facing the shell. 
 
     
     
       16. The system of  claim 15 , wherein the shell contains a plurality of membrane tubes, spaced apart from one another, and wherein the membrane tubes share a common exit port configured to provide a H 2 -containing stream having a purity of at least 95 mole % H 2 . 
     
     
       17. The system of  claim 16 , wherein the shell further comprises tube supports, the tube supports configured to stabilize the membrane tubes contained within the shell. 
     
     
       18. The system of  claim 15 , wherein the system comprises the aromatization reactor vessel and from one to seven additional aromatization reaction vessels, configured in series, wherein the H 2  removal system is positioned between any two reactor vessels. 
     
     
       19. The system of  claim 18 , wherein the H 2  removal system is after the third or fourth vessel in the series. 
     
     
       20. The system of  claim 19 , wherein the aromatization reactor vessel before the H 2  removal system has an amount of catalyst less than an amount of catalyst in the next reactor vessel in the series.